In industrial process measurements technology, especially also in connection with the automation of chemical or other engineered processes and/or the automatic control of industrial plants, measuring devices installed near to the process, so-called measuring field-devices are used, which serve for producing analog or digital, measurement values representing chemical and/or physical, process measured variables and for making available measurement value signals ultimately carrying these measurement values, for example in the form of data telegrams. The process variables to be registered can include, for example, a mass or volume flow, e.g. flow rate, a density, a viscosity, a fill or limit level, a pressure or a temperature, or the like, of a liquid, powdered, vaporous or gaseous medium, which is conveyed, or stored, in a containment, such as e.g. a pipeline or a tank.
For registering such process variables, field devices of the described kind include appropriate physical-to-electrical, or chemical-to-electrical, measuring transducers, as well as a measuring device electronics connected to the measuring transducer.
The transducer is most often installed in a wall of the containment, or in the course of a line, e.g. a pipeline, conveying the medium, and serves for producing an electrical measurement signal appropriately corresponding to the process variable to be registered.
For processing the measurement signal, the transducer is connected with an operating and evaluating circuit provided in the measuring device electronics for the further processing or evaluating of the at least one measurement signal as well as for the generation of corresponding measurement value signals. In a large number of field devices of the described kind, the measuring transducer for producing the measurement signal is additionally so activated by a driver signal generated at least at times during operation by an operating circuit provided in the measuring device electronics, that it acts on the medium in a manner suited for the measurement at least mediately or, however, also via a probe directly contacting the medium, in order to provoke reactions there appropriately corresponding with the measured variable to be registered. The driver signal can, in such case, be appropriately controlled, for example with respect to an electrical current, or voltage, level and/or a frequency. Examples of such active transducers, thus transducers appropriately converting an electrical driver signal in the medium, include, especially, flow measuring transducers serving for measuring, at least at times, flowing media, e.g. transducers with at least one coil activated by a driver signal and producing a magnetic field, or at least one ultrasonic transmitter activated by a driver signal, or, however, also fill level and/or limit level transducers serving for measuring and/or monitoring fill levels in a container, such as e.g. those with freely radiating, microwave antennas, Goubau lines or vibrating immersion elements.
For accommodating the measuring device electronics, measuring field-devices include, further, a relatively robust, especially shock, pressure and/or weather resistant, electronics housing. This can, as proposed e.g. in U.S. Pat. No. 6,397,683 or WO-A 00/36379, be arranged remotely from the field device and be connected therewith only via a flexible cable; it can, however, also, as shown e.g. in EP_A 903 651 or EP-A 1 008 836, be arranged directly on the measuring transducer or on a transducer housing separately housing the transducer. Often, the electronics housing serves, as shown, for example in EP-A 984 248, U.S. Pat. No. 4,594,584, U.S. Pat. No. 4,716,770 or U.S. Pat. No. 6,352,000, also for accommodating some mechanical and/or electromechanical components of the transducer, such as e.g. membrane, rod, sleeve or tubular, deformation or vibration elements deforming during operation due to mechanical effects; compare, in this regard, also the above-mentioned U.S. Pat. No. 6,352,000.
With measuring devices of the aforementioned kind, the measuring device electronics is usually electrically connected, via corresponding electrical lines and/or wirelessly via radio, with a superordinated electronic data processing system most often spatially removed from the measuring device and most often also spatially distributed. To such data processing system, the measurement values produced by means of the measuring device are forwarded, near in time, by means of a measurement value signal bearing them.
Measuring devices of the described kind are, additionally, usually connected with one another and/or with corresponding electronic process controls by means of a wire- or radio-based, data transmission network provided within the superordinated data processing system. The electronic process controls can include programmable logic controllers installed on-site and process control computers installed in a remote control room. To these, the measurement values produced by means of the measuring field device are forwarded, digitized in suitable manner and appropriately coded. By means of the process control computers, the transmitted measurement values can, using correspondingly installed software components, be further processed and visualized as measurement results e.g. on monitors and/or transformed into control signals for other field devices embodied as control elements, such as magnetic valves, electric motors, etc. Accordingly, the data processing system also usually serves for conditioning the measurement value signal delivered from the measuring device according to the requirements of downstream data transmission networks, for example for suitably converting such to digital form and, as required, for conversion into a corresponding telegram, and/or the data processing system may serve for on-site evaluation. For such purpose, provided in such data processing systems, electrically coupled with the relevant connecting lines, are evaluation circuits, which pre- and/or further-process, as well as, if required, suitably convert, the measurement values received from the pertinent measuring device. Serving for data transmission in such industrial data processing systems are, at least sectionally, fieldbusses, especially serial fieldbusses, such as FOUNDATION FIELDBUS, CAN, CAN-OPEN RACKBUS-RS 485, PROFIBUS, etc. or, for example, also networks based on the ETHERNET standard, as well as the corresponding, most often application-spanning, standard transmission protocols.
Usually also implementable by means of a control computer are, besides the mentioned process-visualizing, -monitoring and -control, also remote servicing, parametering and/or monitoring of the attached field, measuring devices. Accordingly, modern field devices permit, besides the actual measurement value transmission, also transmission of various setting and/or operating parameters used in the field device, such as e.g. calibration data, measurement value ranges, or also diagnosis information internally generated in the field devices. In line with this, it is possible most often likewise to send operating data, selected for the field device, to the field device via the aforementioned data transmission networks, which are most often hybrid as regards transmission physics and/or transmission logic.
Besides the evaluating circuits required for the processing and converting of the measurement values delivered by the connected measuring devices, superordinated data processing systems of the described kind have most often also electrical supply circuits serving for supply of the connected field devices with electrical energy, or power. Such supply circuits provide an appropriate supply voltage, which can, in appropriate circumstances, be fed directly from the connected fieldbus, for the relevant measuring device electronics and which drives the electrical lines connected thereto, as well as the electrical currents flowing through the associated measuring device electronics. A supply circuit can, in such case, be assigned to exactly one field device and be accommodated together with the evaluating circuit assigned to the particular measuring device, for example combined to a corresponding fieldbus adapter, in a shared housing embodied e.g. as a hat-rail module. It is, however, also quite usual, to accommodate such superordinated evaluating circuits and supply circuits each in separate, even spatially separated housings and to wire them appropriately together over external cables.
Examples with further details for such measuring field-devices known per se to those skilled in the art or also such measuring arrangements such as are formed by interplay of field device and data processing system are described in, among others, WO-A 06/111573, WO-A 06/002910, WO-A 03/048874, WO-A 03/098154, WO-A 03/017149, WO-A 02/44661, WO-A 02/45045, WO-A 02/103327, WO-A 02/086426, WO-A 01/02816, WO-A 01/14968, WO-A 00/77585, WO-A 00/77583, WO-A 00/48157, WO-A 00/36379, WO-A 00/14485, WO-A 95/16897, WO-A 88/02853, WO-A 88/02476, U.S. Pat. No. 7,134,348, U.S. Pat. No. 7,133,727, U.S. Pat. No. 7,124,239, U.S. Pat. No. 7,075,313, U.S. Pat. No. 7,073,396, U.S. Pat. No. 7,040,181, U.S. Pat. No. 7,032,045, U.S. Pat. No. 6,889,150, U.S. Pat. No. 6,854,055, U.S. Pat. No. 6,799,476, U.S. Pat. No. 6,776,053, U.S. Pat. No. 6,769,301, U.S. Pat. No. 6,763,729, U.S. Pat. No. 6,633,826, U.S. Pat. No. 6,601,005, U.S. Pat. No. 6,577,989, U.S. Pat. No. 6,662,120, U.S. Pat. No. 6,640,308, U.S. Pat. No. 6,634,238, U.S. Pat. No. 6,601,005, U.S. Pat. No. 6,574,515, U.S. Pat. No. 6,564,612, U.S. Pat. No. 6,535,161, U.S. Pat. No. 6,512,358, U.S. Pat. No. 6,505,519, U.S. Pat. No. 6,487,507, U.S. Pat. No. 6,480,131, U.S. Pat. No. 6,476,522, U.S. Pat. No. 6,397,683, U.S. Pat. No. 6,352,000, U.S. Pat. No. 6,311,136, U.S. Pat. No. 6,285,094, U.S. Pat. No. 6,269,701, U.S. Pat. No. 6,236,322, U.S. Pat. No. 6,140,940, U.S. Pat. No. 6,014,100, U.S. Pat. No. 6,006,609, U.S. Pat. No. 5,959,372, U.S. Pat. No. 5,796,011, U.S. Pat. No. 5,742,225, U.S. Pat. No. 5,742,225, U.S. Pat. No. 5,706,007, U.S. Pat. No. 5,687,100, U.S. Pat. No. 5,672,975, U.S. Pat. No. 5,604,685, U.S. Pat. No. 5,535,243, U.S. Pat. No. 5,469,748, U.S. Pat. No. 5,416,723, U.S. Pat. No. 5,363,341, U.S. Pat. No. 5,359,881, U.S. Pat. No. 5,231,884, U.S. Pat. No. 5,207,101, U.S. Pat. No. 5,131,279, U.S. Pat. No. 5,068,592, U.S. Pat. No. 5,065,152, U.S. Pat. No. 5,052,230, U.S. Pat. No. 4,926,340, U.S. Pat. No. 4,850,213, U.S. Pat. No. 4,768,384, U.S. Pat. No. 4,716,770, U.S. Pat. No. 4,656,353, U.S. Pat. No. 4,617,607, U.S. Pat. No. 4,594,584, U.S. Pat. No. 4,574,328, U.S. Pat. No. 4,524,610, U.S. Pat. No. 4,468,971, U.S. Pat. No. 4,317,116, U.S. Pat. No. 4,308,754, U.S. Pat. No. 3,878,725, US-A 2006/0179956, US-A 2006/0161359, US-A 2006/0112774, US-A 2006/0096390, US-A 2006/0081067, US-A 2005/0139015, US-A 2004/0117675, EP-A 1 158 289, EP-A 1 147 463, EP-A 1 058 093, EP-A 984 248, EP-A 591 926, EP-A 525 920, DE-A 103 25 277, DE-A 44 12 388 or DE-A 39 34 007.
In modern measuring field devices, the operating and evaluating circuit is usually formed by means of a re-programmable microcomputer, as well as program code correspondingly executed therewith. The program code is at least partially provided by means of software. The software is usually, at least in part, embodied as hardware-near software, conventionally also referred to as firmware, and is, before start-up of the field device, persistently programmed into non-volatile memories, e.g. a PROM or an EPROM, of the microcomputer, in order to be able to be loaded, as required for the operation of the field device, into a volatile data memory, e.g. a RAM, serving as working memory. “Persistent” means in this case that the software, on the one hand, remains stored following loss of power and so remains executable following re-start of the microcomputer, and that, on the other hand, the software stored within the measuring device can be re-programmed in part, or also can be completely overwritten. During start-up, the microcomputer is most often brought so far into operation, using permanently programmed firmware, the so-called bootstrap loader, implementing the booting, that at least communication of the field device with the superordinated data processing system and activation of further software components required for the actual measurement operation are enabled.
As a result of application of ever more powerful micro- and/or signal-processors for such programmable microcomputers, the functionalities implemented in the field device, especially also measurement signal processing, as well as also the ascertaining of the measurement values based thereon, or their visualization on-site, can, on the one hand, be embodied very complexly, while, on the other hand, however, they can also be customized to be application specific to high degree, especially also branch- and/or customer-specific; this customizing can, on occasion, also be accomplished first on-site, after installation of the field device and its start-up. Associated with the growth in power of the microcomputers, modern field devices additionally permit, beyond the actual measurement value generation as primary function of field devices, implementation to an increasing degree of functionalities which yet more support an efficient and safe conducting of the process being followed. Such secondary functionalities can include, for example, the storing of measurement and/or operational data in history memories, the ascertainment of complex measured variables using interaction with other field devices, control (both open-loop and closed-loop) functions using interaction with process control elements, such as perhaps valves or pumps, internal or external monitoring, validation and/or diagnosis functions, internal functions being such as concern the field device itself, and external functions being those directed at the monitored industrial process installation. Further, such additional functionalities can relate e.g. also to the start-up of the field device as well as its being tied into the data transmission system. Due to this expanded functionality of modern measuring field devices, to an increasing degree, process control functions can be shifted into the field, so that the process control system can be correspondingly organized decentrally. Examples of such re-programmable and thus re-configurable field devices, whose functionalities are application-specifically adaptable also after installation and start-up, especially also during operation, are shown in, among others, the already mentioned U.S. Pat. No. 7,124,239, U.S. Pat. No. 6,633,826, U.S. Pat. No. 6,854,055, WO-A 01/14968, WO-A 00/77585, WO-A 00/77583, WO-A 00/48157, WO-A 03/098154 or WO-A 06/111573.
The growth of functionality shifted into the field device means, on the one hand, also an increasing individualizing of field devices of the described kind, and, on the other hand, for the manufacturer, besides an increased developmental and manufacturing complexity, especially also a significant logistical complexity. Equally, however, also the selection of the right functionalities represents for the user a great effort as regards specifying the requirements for the field device to be installed, this both because of the scarcely any longer manageable multiplicity of the currently or also future offered, basic- and special-functionalities, as well as also due to the high variability in the process-plants and/or -flows to be monitored by the particular field device, for example as a result of operationally varying media or varying media types, especially as regards their flow indices and their compositions. As a result, manufacturers of such field devices are increasingly beginning to offer programs supporting planning. With the help of these programs, parameters relevant for the process measuring point formed by means of the field device can be ascertained very comfortably in advance, perhaps also via Internet dialog with a host computer installed manufacturer-side. Based thereon, it is also possible directly to initiate an ordering of such a field device optimized with respect to the actual application. Examples of such planning and ordering programs, possibly also communicating via Internet, are described in, among others, U.S. Pat. No. 6,889,150, US-A 2007/0067512, US-A 2006/0173836 or WO-A 02/44661.
A disadvantage of such planning and ordering programs is, however, to be seen in that, on the one hand, for optimizing the field device, especially for the matching of its functionalities to be implemented by means of the microcomputer, a considerable, sometimes unacceptably high number of parameters specifying the application need to be asked for, while, on the other hand, many of the parameters specifying the actual measuring point may not even yet be available at the time of ordering, be such due to the fact that that part of the plant does not yet exist and/or due to information still being absent as regards the interactions between process plant and the field device to be ordered. Furthermore, it is to be assumed that, as a result of further developments within the process plant as well as also as a result of improvement of the algorithms generating the measurement value, repeatedly a reconfiguring of the installed hardware will be necessary for field devices of the type being discussed and will involve introduction of new e.g. individual setting parameters, individual calculating routines, comprehensive operating and processing programs or software providing communication routines.